The commonly used Gregorian calendar is based on the Sun's movement around Earth. The Sun only moves around the northern hemisphere, though. As most cultivated civilizations developed in Europe, no one has ever really cared; however, once the Australians also started to measure time, it became quite clear that any non-Australian would never be able to fully understand their methods. All in all, an Australian year can equal to just about anything, depending solely on the will of the measurer. If you have a little penis it is called a pin in australia